Violet tetrachlorindigo and process of making same.



UNITED sTATEs PATENT OFFICE.

AUGUST STOCK, OF H6CHST-ON-THE-MAIN, GERMANY, ASSIGNOR TO FARBWERKE VORM. MEISTER LUCIUS & BRUNING, 0F HbcHsT-oN-THE-MAIN, GERMANY, A GOR- PORATION OF GERMANY.

VIOLET TETRACHLORINDIGO AND PROCESS OF MAKING SAME.

No Drawing.

many, have invented certain new and, useful Improvements in Violet Tetrachlorindigo and Processes of Making Same, of which the following is a specification.

I have found that a tetrachlorindigo of great value is obtained by transforming the 4.5-dichlor-2-nit-robenzaldehyde into indigo by condensation with bodies of the formula: CH .;COR, wherein R stands for hydrogen or an organic radical, and by then treating the condensation product with alkali. The tetrachlorindigo thus obtained dyes beautiful violet tints with a red hue.

The 4.5-dichlor-2-nitrobenzaldehyde is produced by nitrating the 4.5-dichlorbenzaldehyde; when crystallized in benzene it forms yellow prisms meltin at 73 C. By condensing-it with acetone by means of an alkali, the dichlorphenyllactomethylketone, melting at 116 C., is obtained, which is converted into tet-rachlorindigo by the further action of the alkali.

Example 1 Ten parts by weight of 4.5- dichlor-2nitrobenzaldehyde are dissolved in 180 parts of acetone, there is then added a solution of 3 parts of crystallized sodium sultite in 120 parts of water, and the mixture is stirred for one hour at- 5 C. To the dichlorphenyllactomethylketone thus formed is added a solution of 5 gr. of calcined sodium carbonate in 50 parts of water, and the whole is heated for some hours to 3040 C. The tetrachlor-indigo thus separated is filtered,

Specification of Letters Patent. Application filed March 7, 1912. Serial No. 682,278.

Patented Jan. 14,1913.

Washed with acetone and subsequently with water, and dried.

The 5, 6, 5 6 tetrachlorindigo is a violet powder, insoluble in water, very slightly soluble in acetone and chloroform with a violet color, in glacial acetic acid with a blue color, in cold concentrated sulfuric acid with a dull yellowish-gray color which turns green when heated on the water-bath, dissolving in an alkaline-hydrosulfite solution to a yellow vat which dyes cotton and wool beautiful reddish-violet tints.

Having now described my invention, what I claim, is:

1. The process of manufacturing a violet tetrachlorindigo, which consists in condensing 4.5-dichlor-2-nitrobenzaldehyde with a body containing the group CH COR, and treating the condensation product with an alkali.

2. As a new'product, the 5, 6, 5, 6 tetsoluble in acetone and chloroform with a violet color, in glacial acetic acid with a blue'color, in cold concentrated sulfuric acid with a dull yellowish-gray color which turns green when heated on the water-bath, dissolving in an alkaline-hydrosulfite solution to a yellow vat which dyes cotton and wool beautiful reddish-violet tints.

In testimony whereof, I afiix my signature in presence of two witnesses.

' AUGUST STOCK. Witnesses:

EAN GRUND, CARL GRUND. 

